1. Field of the Invention
The present invention relates to a liquid crystal display (LCD) device and method for fabricating the same, and more particularly, to a method for regulating the amount of liquid crystal in an LCD device.
2. Discussion of the Related Art
Among flat panel display devices, liquid crystal display (LCD) devices have been generally used in notebook computers, monitors, spacecraft, airplanes, etc., due to their advantages such as low power consumption and portability.
Hereinafter, an LCD device according to the related art will be explained with reference to the accompanying drawings. FIG. 1 is a cross-sectional view illustrating an LCD device according to the related art.
Referring to FIG. 1, the LCD device includes lower and upper substrates 10 and 20 facing each other with a predetermined gap therebetween, and a liquid crystal layer 40 between the lower and upper substrates 10 and 20 and sealed by a sealant 30.
Although not shown, the lower substrate 10 includes gate and data lines crossing each other to define a pixel region, a thin film transistor as a switching element formed adjacent to a crossing of the gate and data lines, and a pixel electrode connected to the thin film transistor and formed in the pixel region.
Although not shown, the upper substrate 20 includes a light-shielding layer to prevent a light leakage in areas except the pixel region, a color filter layer of red (R), green (G) and blue (B) in the area corresponding to the pixel region to display colors images, and a common electrode on the color filter layer.
The LCD device is manufactured by preparing the lower and upper substrates and forming a liquid crystal layer between the prepared lower and upper substrates. The liquid crystal layer may be formed by an injection method or dispensing method.
For the injection method, a sealant having an inlet is formed on any one of the lower and upper substrates, and the lower and upper substrates are bonded to each other. Then, liquid crystal is injected into a space between the lower and upper substrates through the inlet.
For the dispensing method, a sealant without an inlet is formed on any one of the lower and upper substrates, and liquid crystal is dispensed on any one of the lower and upper substrates. Then, the lower and upper substrates are bonded to each other.
The injection method is disadvantageous for large-size LCD devices in that it takes a long time to inject liquid crystal between the two large substrates. Accordingly, the dispensing method is generally used to fabricate large-size LCD devices.
In the injection method, it is not required to determine an amount of liquid crystal to be injected because liquid crystal is injected into the space between the two substrates after bonding the two substrates to each other. On the other hand, it is important to determine an appropriate amount of liquid crystal to be dispensed, because the two substrates are bonded to each other after dispensing liquid crystal onto any one of the two substrates in the dispensing method.
The amount of liquid crystal to be dispensed is currently determined based upon the size and height of the LCD panel. However, it is difficult to determine the precise amount of liquid crystal due to various conditions. An insufficient amount of liquid crystal generates unfilled regions in the LCD panel, while an excess amount of liquid crystal generates overfilled regions, thereby degrading the picture quality. The LCD panels having these unfilled or overfilled regions may be discarded, thereby decreasing yield and increasing costs.